Bump seaborn from 0.11.1 to 0.11.2 in /requirements/CI-tests-pip

Bumps [seaborn](https://github.com/mwaskom/seaborn) from 0.11.1 to 0.11.2.
- [Release notes](https://github.com/mwaskom/seaborn/releases)
- [Changelog](https://github.com/mwaskom/seaborn/blob/master/doc/whatsnew.rst)
- [Commits](mwaskom/seaborn@v0.11.1...v0.11.2)

---
updated-dependencies:
- dependency-name: seaborn
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

requirements/CI-tests-pip/requirements.txt

@@ -7,7 +7,7 @@ numpy==1.20.3
 pandas==1.2.4
 pytest==6.2.4
 pytest-xdist==2.3.0
-seaborn==0.11.1
+seaborn==0.11.2
 sortedcontainers==2.4.0
 tqdm==4.61.2
 tskit==0.3.7